INTRODUCTION
A partial discharge (PD) is short release of current caused by the buildup of electric field intensity in a finite region. In high voltage devices, such as transformer, PDs can be symptomatic of problems within the device such as floating components and insulation flaws. When a transformer is first manufactured, PD detection can be used as a tool to judge the state of the device and the quality of its manufacture. In addition, as the transformer ages, faults in the device can be created. Over time, electrical and mechanical stresses can damage materials within the transformer, including the winding and the paper insulation lining the walls of the transformer tank. If the damage is not detected or corrected, the faults can cause the transformer to operate outside of its normal parameters and eventually a catastrophic failure will occur, causing potential damage to surrounding equipment and facilities, as well as lost revenue due to an unscheduled power outage [1].
In a modern high voltage power system, PD detection is used to monitor the state of health of a transformer in service and helps plant managers schedule device maintenance. The primary methods of PD detection are based on the observable electric and acoustic characteristics of the phenomenon [2].
In this paper proposes the Partial discharge pattern analysis in cylindrical insulators model by using the electromagnetic
analysis. The study of three insulators, namely air, oil and resin, in the cylindrical model with the electrode is presented.
The insulator models are shown in Fig.1 that have three types of the electrode. The investigation would like to show the
performance of the insulator. The study, analysis and design, for finding the dielectric loss and PD value, can classify the insulator.
The rest of this paper is organized as followed: Section 2 presents characteristic of insulator. Theory of PD is discussed in Section 3. Section 4 proposes model of three insulators. Experimental result of test results are shown in Section 5. Finally, the conclusion is given in Section 6